Peel the potatoes and cut into chunks. Start them boiling.
Meanwhile, start green beans boiling.
Meanwhile, brown ground beef.
Slice onions and spray casserole dish with non-stick coating.
Place the browned ground beef in the bottom of the casserole dish. Cover with half of the cheese (tearing cheese slices into chunks if using) and half of the sliced onions.
Add green beans next, and repeat cheese & onion layers.
Drain potatoes, add milk and butter in your preferred amounts and mash. I use about 2 tablespoons butter & add milk until the consitancy is right.
Spread mashed potatoes over top of casserole.
Sprinkle with additional cheese and breadcrumbs followed by paprika if desired, otherwise just with paprika.
Bake for about 20-30 minutes in a 400 oven until top of mashed potatoes is golden and cheese is well melted. May be prepared in advance, refridgerated and baked later.
Hints: if this is too bland, some suggestions to spice it up: try adding garlic, worcestershire sauce and other spices when browning beef. Add paprika and garlic powder to the potatoes while mixing. Use jalapeno cheese.